Soil erosion is an almost inevitable natural phenomenon that has become a greater concern in recent years due to the worsening climate situation – in Italy, for example, 132 extreme weather events were recorded between January and July 2022, a higher number than the annual average over the last decade – combined with long periods of drought.
Strong winds, heavy rain, hail and runoff tend to remove the surface layer of exposed soils, which often include organic matter and seeds. Climate change facilitates erosion, making it not only inevitable but also hazardous if left uncontrolled.
It’s essential to counter or mitigate the phenomenon: soil provides us with food, biomass and raw materials; human activities take place on it and it’s part of the landscape and our cultural heritage.
Which structures are more subject to surface erosion?
The areas of application most affected by the erosive action of the climate are:
- slopes and the sides of landfills and contaminated sites, and those that have been grassed for appreciable aesthetic improvement;
- reinforced earth structures, more specifically terracing in vineyards and the embankments of canals or rivers;
- ascending/descending ramps from flyovers, tunnel entrances and noise barriers on roads and railways;
- dry, rocky slopes, of all angles, that shape the terrain of Italy.
The effects of surface erosion
The uncontrolled removal of the surface topsoil and the failure of vegetation to take root results in ‘thinning’ of the soil and a risk to the stability of sloping areas.
What can be done to prevent surface erosion?
We should begin by pointing out that a case-by-case assessment is required that considers many variables, such as the nature and uniformity of the soil, the slope gradient, the type of slope (dry or rocky) and the weather conditions in the area where intervention work is to be carried out.
In general, vegetation, whatever type it is, has a natural ability to protect soils from erosion. So the best course of action is to quickly encourage grassing and then apply biodegradable mats made of jute, straw, coconut and cellulose fibre, which can also be pre-seeded.
TeMa Geo Solutions recommends biomats such as Ecovermat, Ecovermat P and PC, and Ecovernet.
Alternatively, or combined with these, synthetic geomats, mainly made of polymer monofilaments, can be used.
Once laid, they are covered with another layer of soil: in this way, the roots of growing vegetation will become entangled with the geomat, creating an almost permanent erosion protection system.
Once again, TeMa Geo Solutions offers a wide range of geomats to choose from.
Uncertain about what to choose? We can help you. CONTACT US!
Hearing the noise of traffic outside your window all day long is irritating and distracting and, in the long term, also harmful to your health.
This is why the WHO and a number of laws govern the use of noise remediation systems in cities: the Framework Law no. 447 of 1995 for Italy and the European Directive on Environmental Noise no. 49/2022. If the cause of the noise cannot be addressed, the solution is to install protective barriers. Various kinds can be used, but in this case we focus on reinforced earth structures that require specific measures, which we discuss here.
What do reinforced earth noise barriers consist of?
For this type of embankment with its typical trapezoidal shape, earth is used that will be covered by vegetation over time. Geosynthetic reinforcements and geogrids are added to support the earth, which already has good compressive strength. These are inserted horizontally into the ground and develop friction and tension that stabilise the structure, increasing its resistance to stress.
The TeMa Geo Solutions offer includes the X-Grid Pet PVC range of geogrids, with different resistance values, which are ideal for all kinds of contexts.
Another aspect to bear in mind is surface erosion of the soil: to counteract this, synthetic geomats are applied, also with a mulching function to encourage the growth of grass cover, or natural fibre bionets.
Also in this case, TeMa Geo Solutions offers a wide choice ranging from Ecovermat F Grass and Ecovernet FJ to the K-Mat range.
Why use a vegetation barrier as a protective noise barrier?
A vegetation barrier has an unquestionable ability to limit the spread of sound waves: some of them are absorbed, some reflected and some deflected. As a result, the amount of sound waves reaching the receiver is greatly reduced and noise can be dampened by several decibels.
The advantages of a reinforced earth sound-deadening barriera
Creating reinforced earth structures brings considerable advantages:
- it costs less because you can often use earth available on-site
- no special maintenance is required other than regular trimming.
- it helps the environment and integrates with it: the use of vegetation also reduces vehicle emissions by absorbing CO 2 and purifying the air.
In recent years, reinforced earth structures have been particularly popular in projects due to their excellent functional and aesthetic importance in the residential building and public building industries.
Such intervention works achieve the best results by allowing the soil and geosynthetics to “work in synergy”, each one with its own features of ensuring the stability of the work as a whole.
It’s easy to see the high environmental value of such solutions, but let’s take a closer look at the two major factors in reinforced soil works. In this way, we can understand how and why, working together, they lead to amazing results, also in aesthetic terms.
What are reinforced earth structures?
They are structural intervention works in various gradients and dimensions aimed at retention and/or stabilisation. We can identify a few main areas of application:
- Road and railway embankments.
- Restoration and consolidation of collapsed soil on a road.
- Construction of ramps for ascending and descending flyovers.
- Canal or river bank elevations.
- Rockfall barriers.
- Noise barriers along roads or railways.
- Widening of elevated car parks.
- Construction of terracing systems in vineyards.
- Soil consolidation at tunnel entrances.
What are geogrids and why are they often the best solution?
Soil has the intrinsic features of friction and compressive strength, but practically no tensile strength. This is not enough to ensure the stability of a structure.
Major slopes, weather conditions, proximity to embankments, etc. can erode soil, causing landslides and subsidence. For reinforced earth structures, it’s therefore necessary to use geogrids, two-dimensional structures horizontally inserted into soil, which integrate with it without deforming. Their open-mesh structure develops “passive” resistance, thereby increasing the stabilising effect.
This bonding exploits the abilities of the two construction elements, making the entire structure more efficient.
Naturally, the feasibility of retaining works needs to consider:
- the intrinsic characteristics of the soil, such as grain size, the degree of thickening and shear strength, as well as the dilatancy phenomenon;
- the characteristics of the geogrids, such as tensile strength and stiffness, the use of raw materials (polymers) that can also withstand harsh chemical and physical conditions (attacks by chemical agents, soil pH, etc.), and the appropriate geometric structure.
Eventually, grass will grow and none of the intervention work will be visible: a really attractive and natural reinforced structure. In addition to its aesthetic function, greening also plays an important role in helping the natural friction of soil.
Find out more about our products here.
Our passion for work does not stop, it simply continues at our company, in a little more limited way. You certainly cannot see us running up and down building sites or going in and out of our research labs, but we can assure you that we are still working on our production of geosynthetic products with the same commitment and perseverance in order to formulate new projects and develop ideas that we will see materialised soon, once everything has ended.
TeMa and Geosynthetic Products
TeMa Geo is the TeMa division created almost thirty years ago with the aim of exploring and expanding the world of geosynthetics, which it still does today. By “geosynthetic products” we generally mean all categories of synthetic coverings that are not only used in contact with earth or other building materials but are also appreciated for their use in various building fields. In the building industry, their main advantage is that they are user-friendly in technical terms, which is why engineers and planners prefer them to other technical solutions.
The Advantages of Geosynthetics
The advantages of geosynthetic options not only lies in the fact that they are easy to use but also in their cost-effectiveness: certainly less expensive, they provide excellent performance that remains unchanged over time. Furthermore, their versatile use makes them the ideal solution to various on-site problems.
Geosynthetic Products “In the Field”: the Serravalle Project
In more practical terms, today we want to tell you about the intervention works we carried out in the Piedmont region in 2016. It involved extension works for Serravalle Retail Park. In preparation for the works, we had to make the slope in front of the new complex safe. In order to proceed, we had to prepare several reinforced soil structures, separating them into banks, and solve the problems of surface drainage for the management of water, whose catchment area was located above the area.
For works of such magnitude, we used geogrids from the XGrid PET-PVC range as a structural element. In addition, to avoid any seepage in the future, drainage elements were installed close to the reinforced structures of the horizontal sections of each berm. This is just one of our products and one of the many fields of application explored by TeMa.
To discover all our membranes, visit our section dedicated to products.